I tried the new version, and it seems to be working great. Thank you.
As a side note, as I've gone through all this various testing, I've come to believe that it would actually be good to address point B from my original posting. I don't think it's urgent, but it probably should be included in some future fix. That would make AM perform the same way at least the Microsoft family of products do, and more importantly, it gives the user some confirmation that meeting invitees know about recent changes.
In any case, thanks again for addressing the core problems so quickly!